Engine cylinder valve



2 1940 A. v. D. WILLGOOS 2,191,333

ENGINE CYLINDER VALVE Filed Sept. 30. 1938 A TTORNE Y Patented Feb. 20,1940 UNITED STATE s PATENT OFFICE ENGINE CYLINDER VALVE Andrew v. n.Willgoos, West ammo, Conm, as

signor to United Aircraft Corporation, East Hartford, Conn., acorporation of Delaware Application September 30, 1938, Serial No.232,497

8 Claims.

An object of the invention resides in the provi-- sion of an improvedcylinder valve arrangement including an improved and simplifiedconstruction for connecting the valve closing spring to the end of thevalve stem.

A further object. resides in the provision of an improved valveconstruction in which one of the elements utilized to connect the end ofthe valve closing spring to the valve stem also serves the additionalpurpose of limiting the inward move-v ments of the valve into thecylinder, particularly in case of breakage of the spring or the springconnecting means.

Other objects and advantages will be more 20 particularly pointed outhereinafter or will be,-

' come apparent as the description proceeds.

In the accompanying drawing, in which like reference numerals are usedto designate similar parts throughout, thereis illustrated a suitablemechanical embodiment of an engine cylinder valve constructiondisclosing the invention. The drawing, however, is for the purpose ofillustration only and is not to be taken as in any wayv limiting orrestricting the scope of the invention as set forth in the appendedclaims.

In the drawin Fig. 1 is a side elevational view of an engine and a headl4 provided with a beveled sealing surface I6 which cooperates with asimilar sur face provided on the annular valve seat I 8 secured in thecylinder head 20 surrounding the port 22. Above the port 22 the cylinderhead is provided rocker-arm box 26. A tubular guide 28 extends throughthe extension 24 and intothe interior of the rocker arm box terminatingabove the bottom gm of the rocker-arm box as indicated at 88 and isprovided with an annular shoulder 32 which rests upon the bottom of therocker-arm box and pre- 'vents the guide from moving through the exten-'sion 24. The valve stem I2 extends through the I guide 28 and to aposition above the upper end familiar mushroom type having a stemportion l2 with an extension 24 which terminates in a hollow of theguide to receive an abutment structure generally indicated at 34 for theupperor outer end of one or more coiled compression springs, asindicated at 36 and 38, located in the rocker-arm box 26 and surroundingthe portions of the valve guide and valve stem projecting into therockerarm box. The force of the springs 36 and 38 exerted on theabutment 34 tends to raise the valve l8 and maintain it closed againstthe seat l8. The valve is opened by a suitable valve operating device,not illustrated, many forms of which are familiar to the art. Ifdesired, a fixed abutment 4!! and a spring pad 42 may be disposedbetween the lower ends of the springs 36 and 38 and the bottom of therocker-arm box 26 immediately surrounding the valve guide 28 foradjusting the spring tension and to provide a hard bearing surface forthe lower ends of the springs, particularly in those constructions inwhich the cylinder head 28 is made of a relatively soft metal such as analuminum alloy.

The valve stem l 2 is provided near its end opposite the head I4 with acomparatively shallow annular groove 44, preferably having roundedshoulders so that there are no sharp edges on the valve stem to permitlocalized stress concentration which might result in relatively rapiddeterioration of the valve stem in use The abutment 34 comprises a splitsnap ring 46 proportioned to be partly received in the annular groove44, a pair of semi-circular wedges 48 and 58 having axially taperedouter surfaces and a flanged cap generally indicated at 52 including asleeveportion 54 having an axially tapered inner surface dimensioned andproportioned to cooperate with the outer surfaces of the wedges 48 and50, and an annular flanged portion 56 arranged to overlie the upper orouter ends of the springs 36 and 38.

In applying the improved valve retaining organization the valve is firstinserted through the guide 28 and the snap ring 46 applied to the valvestem. The springs 36 and 38 are placed in position upon the abutment 40and pad 42 surrounding the upper ends of the valve stem and uide member.The movable abutment member 5215 then placed in position upon the valvesprings and the springs are compressed to move the member 52 inwardly toa position past the groove 44. With the movable abutment 52 below thesnap ring 46 the wedges 48 and 60 are inserted in position so that theybear at both sides of their internal grooves on the valve stem andtheirinternal grooves, as indicated. at 58, receive the outer portion ofthesnap ring, the inner portion of which is received in the annulargroove 44 springs 33 and 38 may then be released permitting the movableabutment 52 to move outwardly until it wedges upon the wedge members 46and 48 which bear on and become fixed relative to the valve stem l2 bythis wedging action. The outer ends of the springs 26 and 38 will thenbe securely connected to the outer end of the valve stem so that theforce of the springs will urge the valve to seat against the annularseat member 18. The valve guide 28 is dimensioned above the shoulder 32so that its upper or outer end, as indicated at 30, is located at aposition near the terminal position of the undersurfaces of the members46, 48 and 52 during the valve opening travel of these members, as isindicated in broken lines in Fig. 1. With this arrangement, if the valvesprings 36 and 88 should be broken during operation the contact of theundersurfaces of the members 43 and 48, as illustrated, with the upperend 30 of the valve guide 28 will limit the inward movement of the valveso that the valve will not project into the cylinder materially beyondits normal open position. If the member 52 or the springs 36 and 38should be broken and the members 48 and 50 released from their operativeposition, contact of the lower side of the snap ring 46 with the upperend of the valve guide 28 will limit the inward movement of the valve sothat the valve still cannot project into the cylinder materially beyondits normal open position and the piston, not illustrated, will thereforenot be permitted to pound against the head of the valve if the enginecontinues to operate after one valve has been disabled in the mannerindicated above. With this construction only one groove in the valvestem is necessary and only one ring is used to perform the two functionsof retaining the movable spring abutment on the end of the valve stemand limiting the inward travel of the valve in case the springs orabutments fail during operation which construction not only provides amaterial. simplification of the spring retaining and movement limitingarrangement by avoiding the use of. additional parts but also results ina much stronger and more durable valve stem by omitting an additionalgroove be-.

tween the abutment retaining groove'and the valve head.

While a particular mechanical. construction and described, but that suchchanges in the size,

shape and arrangement of parts may be resorted to as come within thescope of the sub-join claims.

Having now described the invention so that other skilled in the artmay'clearly understand the same, what it is desired to secure by LettersPatent is as follows.

What is claimed is: a V

1. An engine valve organization including, a valve having a stemprovided with an annular groove near its outer end, and a snap ringengageable in said groove and providing a shoulderon said stem to limitthe travel of said valve in one direction and provide an anchorage for avalve spring retainer.

- 2. An engine valvegorganization including, a

valve having a stem provided with a shallow an.- nular. groove near itsouter end, a valve-spring, and an abutment for connecting the'outerend Iin the valve stem. The means compressing the of said spring to the outerend of said valve, and a single snap ring engageable in said groove andprojecting beyond the cross-sectional area of said stem to limit thetravel of said valve in one direction and provide an anchorage for saidabutment in operatively connecting the end of said valve spring to saidvalve stem.

3. An engine valve organization including, a valve having a stemprovided with an annular recess near its outer end, a valve spring, anabutment for connecting the outer end of said spring to the outer end ofsaid valve, a tubular guide for said valve stem, and a single snap ringengageable in said recess to provide an anchorage for said abutment andcooperate with the end of said guide to limit the travel of said valvein one direction.

4. Avalve spring retainer and valve travel limiting device comprising, asnap ring simulating a short split tube and having end surfaces adaptedto be engaged with the sides of an annular groove in the outer portionof the valve, a pair of wedge members engageable with the end surfacesonly of said snap ring and bearing on the valve stem, and a flangedabutment engageable with said wedge members and the adjacent end of thevalve spring. a

5.' In combination with a valve having a stem and a head portion and ashallow annular groove in the stem portion at the end thereof oppositesaid head constituting the only irregularityin the cylindrical surfaceof said stem, a tubular guide for said valve, and a valve closing springsurroundinga portion of said stem, means for connecting the-grooved endof said valve stem to the corresponding end of said spring and forlimiting movements of said stem through said guide comprising, a snapring of thin cross-section in said groove, a pair of substantiallysemicircular wedge members engageable with said snap ring but bearing onsaid stem, and a flanged abutment engageable with said wedge members andoverlying the adjacent end of said spring. 7

6. In combination with a valve having a stem and a head portion and ashallow annular groove having rounded shoulders in the stem portion atthe end opposite said head constituting the sole irregularity in thecylindrical surface of said stem, a tubular guide for said valveterminating, when said valve isin closed position, at a distance fromsaid groove substantially equal to the open-' ing travel of said valve,and a valve closing spring surrounding. a portion of said stem, meansfor connecting the grooved end-ofsaidvalve stem to the corresponding endof said spring and for cooperating with the end of said valve guide tolimit movement of said valve through said guide comprising, a snap ringhaving a relatively thin elongated cross-section in said groove, a pairof substantially semi-circular wedge members engageable with the sidesofsaid snap ring, and a .flanged abutment engageable with said wedgemembers and arranged to overlie the adjacent end of said spring.

' 7. In combination with a valve having a stem and a head portion and ashallow annular groove in the stem portion at the end thereof oppositesaid .head, a tubular guide for said valve terminating, when said valveis in closed position, at a distancefrom said groove only slightlygreater than the opening travel of said valve, and a valve closingspring surrounding a portion of said stem, means for connecting thegrooved end of said valve stem to the corresponding end of said aromas 3bearing on the valve stem on each side of said snap ring, and a flangedabutment engaged with said wedge members and overlying the adjacent endsof said spring.

10' 8; In an engine valve combination, a valve having a head portion anda stem portion provided with an annular groove near its end oppositesaid head portion, a tubular valve guide provided in- .termediate itslength with an external annular 1s shoulder supported by the engine, avalve seat supported by the engine, a valve closing sprirt surroundingthe portion of said valve guide on the side of said shoulder remote fromsaid seat. a flanged abutment overlying said spring, wedge membersengaging said abutment, and a snap 5 .ring in said groove and. engagingsaid wedge members to position said abutment with respect to said valvestem and limit the movement of saidvalve stem through said guide in theevent of failure of said spring or said abutment, the 10 v distancebetween said snap ring and the adiacent end oi. said valve guidawhensaid valve is closed against said seat being substantially equal to thenormal opening travel of said valve.

anwvnwmmoos. u

